I want to know the role of "thus" here.
"Thus" is used to express the result or consequence of something. Here, the expression "thus far" is used, which means the result or state of something up until this point. This phrase is similar to "so far", but it is more formal. In this case, "thus far" means that up until this point, the duck was able to avoid the questions of why it is in Central Park. However, this is used in a humorous, metaphorical sense. Here's some more examples of "thus far": Ex: I haven't had anything to eat thus far. Ex: The weather has been bad thus far this week.